Role of computed tomography in transcatheter replacement of ‘other valves’: a comprehensive review of preprocedural imaging

Abstract

Transcatheter procedures for heart valve repair or replacement represent a valid alternative for treating patients who are inoperable or at a high risk for open-heart surgery. The transcatheter approach has become predominant over surgical intervention for aortic valve disease, but it is also increasingly utilized for diseases of the ‘other valves’, that is the mitral and, to a lesser extent, tricuspid and pulmonary valve. Preprocedural imaging is essential for planning the transcatheter intervention and computed tomography has become the main imaging modality by providing information that can guide the type of treatment and choice of device as well as predict outcome and prevent complications. In particular, preprocedural computed tomography is useful for providing anatomic details and simulating the effects of device implantation using 3D models. Transcatheter mitral valve replacement is indicated for the treatment of mitral regurgitation, either primary or secondary, and computed tomography is crucial for the success of the procedure. It allows evaluating the mitral valve apparatus, the surrounding structures and the left heart chambers, identifying the best access route and the landing zone and myocardial shelf, and predicting obstruction of the left ventricular outflow tract, which is the most frequent postprocedural complication. Tricuspid valve regurgitation with or without stenosis and pulmonary valve stenosis and regurgitation can also be treated using a transcatheter approach. Computer tomography provides information on the tricuspid and pulmonary valve apparatus, the structures that are spatially related to it and may be affected by the procedure, the right heart chambers and the right ventricular outflow tract.

Advances in Imaging for Tricuspid Transcatheter Edge-to-Edge Repair: Lessons Learned and Future Perspectives

“…Additional MPR planes parallel to the TV can optimize the visualization of the TV leaflets anatomy and identification of a four-leaflet configuration variant, which is associated with an increased risk of residual TR, especially in patients with a wide coaptation gap or TR jet from the posteroseptal or anteroposterior commissures [36]. It also allows the measurement of the position and extent of the coaptation gap and TV leaflet tethering grade, including tenting height, angle, and area, which is always measured in mid-systole; by aligning the reformation planes with the narrowest portion of the regurgitant orifice during mid-systole, is possible to measure the anatomical regurgitant orifice area, which may represent a flow-independent anatomic parameter of TR severity [35,[37][38][39]. CCT may provide useful information on TV and leaflet anatomy, the valve gap, mechanisms of TR, and the best fluoroscopic angles for coplanar alignment and leaflet grasping strategy [32,34].…”

Cardiovascular imaging updates and future perspectives

“…27 CT is also crucial for the success of transcatheter valve replacement, allowing a complete evaluation of mitral and tricuspid apparatus and biventricular anatomy. 28 Although the 2019 Guidelines on chronic coronary syndrome (CCS) of the European Society of Cardiology changed the current management of affected patients, they could not clarify which type of test, functional or anatomic, should be first chosen in different clinical scenarios of suspected CCS. 29 Stress-echocardiography can rightly be considered very useful, due to its real-time imaging, high temporal resolution, safety, absence of radiation and low cost.…”

“…It has also been shown that psoas muscular attenuation CT measurement (mean HU and high-density/low-density muscle) are independent and incremental predictors of all-cause mortality in patients undergoing TAVI 27 . CT is also crucial for the success of transcatheter valve replacement, allowing a complete evaluation of mitral and tricuspid apparatus and biventricular anatomy 28 …”